Workers recently planted red alder, Oregon ash, Douglas fir and other trees near a stream on property owned by the J. Frank Schmidt & Son Co. nursery near Boring, Ore. Trees and shrubs were planted as part of the Clackamas River Basin Council’s “Save Our Streams” project, which aims to shade waterways.

Stream restoration projects can add up to big orders for producers of native trees and shrubs.

Restoring shade to denuded streams — and thus cooling the water for fish — requires about 2,200 plants per acre.

With about 1.7 million miles of streams across the U.S. needing some degree of restoration, native plants are a potential “huge business opportunity,” said Joe Whitworth, president of the Freshwater Trust conservation non-profit.

“We are in the very early stages of driving demand for this market,” Whitworth said.

For nurseries, the large number of plants involved in environmental restoration projects can be a blessing and a curse.

Selling a massive volume of product in a single transaction has its benefits, but the scale can present practical challenges.

Since the recent recession, project contractors have been less willing to commit to buying plants long before they’re needed, she said.

Contractors are more eager to buy plants that are already available, but anticipating this demand is tricky, said Klest.

“It makes planning harder,” she said.

Each restoration project requires a unique mix of plants, some of which are rarely in demand, she said.

“Once that project is done, that project will never be done again,” Klest said.

The expertise of plant buyers can also be uneven due to turnover rates at various government agencies, said Mike Nehls, owner of Native Grounds Nursery in Brownsville, Ore.

“There’s not a lot of continuum with the workers buying the plants,” he said.

Project managers have increasingly been asking for plants grown near the restoration site, which further complicates matters, said Ann Murphy, marketing director for the Oregon Association of Nurseries.

Despite these challenges, Murphy said interest in native trees and shrubs has grown in the nursery industry.

“The more general nurseries are adding native plants to their inventories,” she said.

Whitworth of the Freshwater Trust said he foresees more stability in the stream restoration market.

Municipalities are required by the federal Clean Water Act to mitigate the rise in water temperatures caused by wastewater treatment facilities, he said.

Many municipalities are choosing to restore streams rather than build cooling towers for waste water, as the environmental “uplift” is comparable while the costs tend to be lower, Whitworth said.

Aside from preventing streams from heating up, trees and shrubs can reduce erosion and absorb excess nutrients, he said.

Scientists are able to quantify these benefits in ways they couldn’t even a few years ago, said Whitworth.

As the role of plants in achieving water quality standards is better understood, such “green infrastructure” will likely become more prominent, he said.

“Nature knows a few things and we should leverage those to our benefit,” Whitworth said.